RAG Pipelines Fail Silently

RAG pipelines have three failure modes: bad retrieval, bad generation, or both. The tricky part? They often degrade slowly, and users stop trusting the system before you notice.

Why RAG Breaks

• Index drift (new docs added, embeddings not updated)
• Query rephrasing changes retrieval
• Model updates change generation style
• Chunking strategy does not match queries

Metrics That Matter

• Retrieval precision (% of retrieved chunks actually used)
• Context relevance (does context answer the query?)
• Answer faithfulness (does output match context?)
• Token efficiency (is context bloated?)

Testing Strategy

Build a test set of queries with known good retrievals. Run it weekly. If precision drops, re-index. If faithfulness drops, tune generation prompt.